Fabricating semiconductor devices such as logic and memory devices typically includes processing a substrate such as a semiconductor wafer using a large number of semiconductor fabrication processes to form various features and multiple levels of the semiconductor devices. Multiple semiconductor devices may be fabricated in an arrangement on a single semiconductor wafer and then separated into individual semiconductor devices.
Semiconductor devices may develop defects during the fabrication processes. Inspection processes are performed at various steps during a semiconductor manufacturing process to detect defects on a specimen. Inspection processes are an important part of fabricating semiconductor devices such as integrated circuits, becoming even more important to successfully manufacture acceptable semiconductor devices as the dimensions of semiconductor devices decrease. For instance, detection of defects has become highly desirable as the dimensions of semiconductor devices decrease, as even relatively small defects may cause unwanted aberrations in the semiconductor devices.
Sensors in wafer inspection systems tend to undersample a defect shape if a point spread function (PSF) size is comparable or smaller than the pixel size of the sensor, resulting in a low-resolution image. Additionally, sensors in wafer inspection systems become saturated above a certain pixel intensity, providing no differentiation between features on the inspected wafer. As such, it would be desirable to provide a system and method that cures the shortcomings of the previous approaches as identified above.